This present invention relates in general to telecommunications systems and more particularly to a method and system for wireless data communications, including a system for dynamically allocating data channels to trunk groups.
Wireless communications systems use electromagnetic radiation to carry encoded data between a transmitter and a receiver. In wireless communication systems that include a central terminal that services a large number of subscriber terminals, each with the capability to receive and transmit data, it is necessary to efficiently use the electromagnetic frequency spectrum to accommodate the largest number of subscribers.
For example, a wireless local loop system may be used to provide service to residential areas. Such environments are typically multi-path environments, which are characterized by radio frequency signals being reflected by intervening objects, such that a large number of duplicate signals may be received at the receiver. In such environments, it is necessary to perform additional signal processing to improve the quality of the received signal.
In addition to the phenomenon of multi-path signal generation, radio frequency licensing entities often allocate available radio frequency spectrum space to telecommunications service providers in segments of varying bandwidth size. The number of users of the system also varies as a function of time, which can cause the signal quality to subscriber terminals that are remote from the central terminal to be degraded even though additional unused system capacity exists that could be used to improve the signal quality. Existing systems and methods for data communications that are used in multi-path environments are not easily reconfigured to accommodate changes in bandwidth, signal strength, number of users, or other variables. Therefore, it is difficult to optimize the data communication systems for the service environment, number of users, licensing variables, and other variables.
Therefore, a system and method for wireless data communications are required that substantially eliminate or reduce the problems associated with conventional systems and methods for wireless data communications.
In particular, a system method for wireless data communications is required that allows the signal strength to users that are remote from the central terminal to be improved when additional system resources are available.
In accordance with the present invention, a method is provided for transmitting data. The method includes receiving a service request for a standby subscriber terminal, such as when a call is placed to or from the standby subscriber terminal. The number of telecommunications channels carried by a trunk group is then changed, such as by increasing or decreasing the number of encoded telecommunications channels carried by the trunk group. The standby subscriber terminal is then assigned to one of the telecommunications channels of the trunk group.
Another embodiment of the present invention is a system for transmitting data. The system includes a central terminal coupled to a telecommunications network. The central terminal transmits and receives channels of data from the telecommunications network. The system also includes a plurality of subscriber terminals. Each subscriber terminal is operable to transmit and receive a channel of data from the central terminal. A trunk group having an effective radiated power level is modulated by a first group of one or more data channels. The effective radiated power level may be increased or decreased as a function of the distance between one or more subscriber terminals and the central terminal. Another trunk group is modulated by another one or more data channels. The effective radiated power level of the other trunk group may be increased or decreased as a function of the distance between the other group of one or more subscriber terminals and the central terminal.
The present invention provides many important technical advantages. One important technical advantage of the present invention is a method for improving the quality of data communications that allows the number of telecommunications channels carried by a trunk group to be dynamically increased and decreased. This dynamic assignment allows signal quality to be improved when system usage is light.
Another important technical advantage of the present invention is a system for transmitting data that allows the amplification power levels of trunk groups to be dynamically assigned. Dynamic assignment of power levels between trunk groups allows power to be reassigned from trunk groups that are servicing subscriber terminals that are near to the central terminal to trunk groups that are servicing subscriber terminals that are remote from the central terminal. Thus, the signal quality may be improved for one channel without adversely affecting the signal quality of other channels.